The Hox gene Abdominal-B antagonizes appendage development in the genital disc of Drosophila

Development ◽  
2001 ◽  
Vol 128 (3) ◽  
pp. 331-339 ◽  
Author(s):  
B. Estrada ◽  
E. Sanchez-Herrero

In Drosophila, the Hox gene Abdominal-B is required to specify the posterior abdomen and the genitalia. Homologues of Abdominal-B in other species are also needed to determine the posterior part of the body. We have studied the function of Abdominal-B in the formation of Drosophila genitalia, and show here that absence of Abdominal-B in the genital disc of Drosophila transforms male and female genitalia into leg or, less frequently, into antenna. These transformations are accompanied by the ectopic expression of genes such as Distal-less or dachshund, which are normally required in these appendages. The extent of wild-type and ectopic Distal-less expression depends on the antagonistic activities of the Abdominal-B gene, as a repressor, and of the decapentaplegic and wingless genes as activators. Absence of Abdominal-B also changes the expression of Homothorax, a Hox gene co-factor. Our results suggest that Abdominal-B forms genitalia by modifying an underlying positional information and repressing appendage development. We propose that the genital primordia should be subdivided into two regions, one of them competent to be transformed into an appendage in the absence of Abdominal-B.


Development ◽  
2000 ◽  
Vol 127 (2) ◽  
pp. 209-216 ◽  
Author(s):  
P.D. Dong ◽  
J. Chu ◽  
G. Panganiban

The Distal-less gene is known for its role in proximodistal patterning of Drosophila limbs. However, Distal-less has a second critical function during Drosophila limb development, that of distinguishing the antenna from the leg. The antenna-specifying activity of Distal-less is genetically separable from the proximodistal patterning function in that certain Distal-less allelic combinations exhibit antenna-to-leg transformations without proximodistal truncations. Here, we show that Distal-less acts in parallel with homothorax, a previously identified antennal selector gene, to induce antennal differentiation. While mutations in either Distal-less or homothorax cause antenna-to-leg transformations, neither gene is required for the others expression, and both genes are required for antennal expression of spalt. Coexpression of Distal-less and homothorax activates ectopic spalt expression and can induce the formation of ectopic antennae at novel locations in the body, including the head, the legs, the wings and the genital disc derivatives. Ectopic expression of homothorax alone is insufficient to induce antennal differentiation from most limb fields, including that of the wing. Distal-less therefore is required for more than induction of a proximodistal axis upon which homothorax superimposes antennal identity. Based on their genetic and biochemical properties, we propose that Homothorax and Extradenticle may serve as antenna-specific cofactors for Distal-less.



Development ◽  
1985 ◽  
Vol 88 (1) ◽  
pp. 85-112
Author(s):  
Jonathan Cooke ◽  
John A. Webber

Xenopus embryos have been selected in which the second cleavage is occuring in a frontal plane, i.e one tending to lie at right angles to the prospective plane of bilateral symmetry for the body pattern. Some of these have been used to deduce a map of the disposition of materials for the normal mesodermal pattern (the normal ‘fate map’) by injecting blastomeres to found fluorescently marked clones from 4- to 32-cell stages. Other such 4-cell embryos have been separated into two isolates across this second cleavage; in fate-map terms, prospective dorsoanterior and posterior isolates. These have been allowed to develop to control axial larval stages, with examination of the time schedule of their gastrulation movements in relation to cofertilized whole controls. The patterns of mesoderm produced have been examined and interpreted in the light of quantitative knowledge about the normal pattern, and our current understanding of the map. A meaningful fate map exists for the egg material even at this early, essentially acellular stage, and it differs appreciably from what might have been expected in view of that traditionally shown for early gastrula stages. The patterns developed in the isolates show that at least in many eggs, widespread information that positively specifies material as to its body position is available from at most 1 h after the events that give rise to bilateral symmetry upon fertilization. This information usually leads to a mosaic development of the appropriate mesodermal part-pattern in dorsoanterior isolates, and frequently allows development that approximates to this in the reciprocal posterior part. Regulation, i.e. the replacement of removed information to specify a development more complete than the normal contribution in isolates, is not observed. The results suggest a revision of former claims for regulative ability in at least this amphibian embryo. They also imply that systems for ascribing position value (positional information) to early embryonic tissue can be diverse in dynamics, even among embryos whose body plans are obviously homologous as are those of vertebrates.



2020 ◽  
Vol 20 (8) ◽  
pp. 1262-1267
Author(s):  
Haojun Yang ◽  
Hanyang Liu ◽  
YuWen Jiao ◽  
Jun Qian

Background: G protein-coupled bile acid receptor (TGR5) is involved in a number of metabolic diseases. The aim of this study was to identify the role of TGR5 after Roux-en-Y gastric bypass (GBP). Methods: Wild type and TGR5 knockout mice (tgr5-/-) were fed a high-fat diet (HFD) to establish the obesity model. GBP was performed. The changes in body weight and food intake were measured. The levels of TGR5 and peptide YY (PYY) were evaluated by RT-PCR, Western blot, and ELISA. Moreover, the L-cells were separated from wild type and tgr5-/- mice. The levels of PYY in L-cells were evaluated by ELISA. Results: The body weights were significantly decreased after GBP in wild type mice (p<0.05), but not tgr5-/- mice (p>0.05). Food intake was reduced after GBP in wild type mice, but also not significantly affected in tgr5-/- mice (p>0.05). The levels of PYY were significantly increased after GBP compared with the sham group (p<0.05); however, in tgr5-/- mice the expression of PYY was not significantly affected (p>0.05). After INT-777 stimulation in L-cells obtained from murine intestines, the levels of PYY were significantly increased in L-cells tgr5+/+ (p<0.05). Conclusion: Our study suggests that GBP up-regulated the expression of TGR5 in murine intestines, and increased the levels of PYY, which further reduced food intake and decreased the body weight.



2021 ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Klaus Reinhardt

AbstractSperm aging is accelerated by the buildup of reactive oxygen species (ROS), which cause oxidative damage to various cellular components. Aging can be slowed by limiting the production of mitochondrial ROS and by increasing the production of antioxidants, both of which can be generated in the sperm cell itself or in the surrounding somatic tissues of the male and female reproductive tracts. However, few studies have compared the separate contributions of ROS production and ROS scavenging to sperm aging, or to cellular aging in general. We measured reproductive fitness in two lines of Drosophila melanogaster genetically engineered to (1) produce fewer ROS via expression of alternative oxidase (AOX), an alternative respiratory pathway; or (2) scavenge fewer ROS due to a loss-of-function mutation in the antioxidant gene dj-1β. Wild-type females mated to AOX males had increased fecundity and longer fertility durations, consistent with slower aging in AOX sperm. Contrary to expectations, fitness was not reduced in wild-type females mated to dj-1β males. Fecundity and fertility duration were increased in AOX and decreased in dj-1β females, indicating that female ROS levels may affect aging rates in stored sperm and/or eggs. Finally, we found evidence that accelerated aging in dj-1β sperm may have selected for more frequent mating. Our results help to clarify the relative roles of ROS production and ROS scavenging in the male and female reproductive systems.



2020 ◽  
Author(s):  
Maik Hintze ◽  
Sebastian Griesing ◽  
Marion Michels ◽  
Birgit Blanck ◽  
Lena Wischhof ◽  
...  

AbstractWe investigated the contribution of apoptosis-inducing factor (AIF), a key regulator of mitochondrial biogenesis, in supporting hair growth. We report that pelage abnormalities developed during hair follicle (HF) morphogenesis in Harlequin (Hq) mutant mice. Fragility of the hair cortex was associated with decreased expression of genes encoding structural hair proteins, though key transcriptional regulators of HF development were expressed at normal levels. Notably, Aifm1 (R200 del) knockin males and Aifm1(R200 del)/Hq females showed minor hair defects, despite substantially reduced AIF levels. Furthermore, we cloned the integrated ecotropic provirus of the Aifm1Hq allele. We found that its overexpression in wild-type keratinocyte cell lines led to down-regulation of HF-specific Krt84 and Krtap3-3 genes without altering Aifm1 or epidermal Krt5 expression. Together, our findings imply that pelage paucity in Hq mutant mice is mechanistically linked to severe AIF deficiency and is associated with the expression of retroviral elements that might potentially influence the transcriptional regulation of structural hair proteins.



Genetics ◽  
2000 ◽  
Vol 155 (2) ◽  
pp. 721-731 ◽  
Author(s):  
Teresa D Shippy ◽  
Jianhua Guo ◽  
Susan J Brown ◽  
Richard W Beeman ◽  
Robin E Denell

Abstract The Tribolium castaneum homeotic gene maxillopedia (mxp) is the ortholog of Drosophila proboscipedia (pb). Here we describe and classify available mxp alleles. Larvae lacking all mxp function die soon after hatching, exhibiting strong transformations of maxillary and labial palps to legs. Hypomorphic mxp alleles produce less severe transformations to leg. RNA interference with maxillopedia double-stranded RNA results in phenocopies of mxp mutant phenotypes ranging from partial to complete transformations. A number of gain-of-function (GOF) mxp alleles have been isolated based on transformations of adult antennae and/or legs toward palps. Finally, we have characterized the mxp expression pattern in wild-type and mutant embryos. In normal embryos, mxp is expressed in the maxillary and labial segments, whereas ectopic expression is observed in some GOF variants. Although mxp and Pb display very similar expression patterns, pb null embryos develop normally. The mxp mutant larval phenotype in Tribolium is consistent with the hypothesis that an ancestral pb-like gene had an embryonic function that was lost in the lineage leading to Drosophila.



2021 ◽  
Vol 22 (10) ◽  
pp. 5116
Author(s):  
Hideki Katow ◽  
Tomoko Katow ◽  
Hiromi Yoshida ◽  
Masato Kiyomoto

The multiple functions of the wild type Huntington’s disease protein of the sea urchin Hemicentrotus pulcherrimus (Hp-Htt) have been examined using the anti-Hp-Htt antibody (Ab) raised against synthetic oligopeptides. According to immunoblotting, Hp-Htt was detected as a single band at around the 350 kDa region at the swimming blastula stage to the prism larva stage. From the 2-arm pluteus stage (2aPL), however, an additional smaller band at the 165 kDa region appeared. Immunohistochemically, Hp-Htt was detected in the nuclei and the nearby cytoplasm of the ectodermal cells from the swimming blastula stage, and the blastocoelar cells from the mid-gastrula stage. The Ab-positive signal was converged to the ciliary band-associated strand (CBAS). There, it was accompanied by several CBAS-marker proteins in the cytoplasm, such as glutamate decarboxylase. Application of Hp-Htt morpholino (Hp-Htt-MO) has resulted in shortened larval arms, accompanied by decreased 5-bromo-2-deoxyuridin (BrdU) incorporation by the ectodermal cells of the larval arms. Hp-Htt-MO also resulted in lowered ciliary beating activity, accompanied by a disordered swirling pattern formation around the body. These Hp-Htt-MO-induced deficiencies took place after the onset of CBAS system formation at the larval arms. Thus, Hp-Htt is involved in cell proliferation and the ciliary beating pattern regulation signaling system in pluteus larvae.



Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 4 ◽  
Author(s):  
Dagmar Jirsová ◽  
Xuejuan Ding ◽  
Kristína Civáňová ◽  
Eliška Jirounková ◽  
Jana Ilgová ◽  
...  

Paradiplozoon hemiculteri (Ling, 1973), a member of the Diplozoidae, parasitizes the gills of Asian fish. Not only is the type material unavailable for this species, the original description was poor and somewhat conflicting, and adequate molecular data were not available. What is more, the available morphological and molecular data are inconsistent and fluctuate significantly. Here, we present a redescription of P. hemiculteri based on morphological and molecular data from new isolates collected from the type host, the sharpbelly Hemiculter leucisculus (Basilewsky, 1855), captured at the neotype locality (Shaoguan, Guangdong Province, southern China); a neotype for P. hemiculteri was designated from this collection. The length and width of the body, buccal suckers, pharynx, attachment clamps, sickle and the central hook handle were all measured and the shape of the anterior and posterior part of the median plate and anterior and posterior joining sclerites accurately documented. Phylogenetic analyses based on the sequences of the second rDNA internal transcribed spacer (ITS2) indicated that all new samples clustered together and differed clearly from sequences attributed to P. hemiculteri, which are deposited in GenBank. Our results confirm that P. hemiculteri is the only diplozoid that has demonstrably been found on the gills of H. leucisculus to date.



1969 ◽  
Vol 62 (2) ◽  
pp. 367-384 ◽  
Author(s):  
A. M. Sackler ◽  
A. S. Weltman ◽  
R. Schwartz ◽  
P. Steinglass

ABSTRACT This report was designed to determine combined effects of maternal endocrine imbalances and abnormal behaviour due to prolonged isolation stress of female mice on the behaviour, developmental growth rate and endocrine function of their offspring. Sixty female albino mice averaging 19 g were divided equally into isolated and control groups. The isolated females were housed singly; control females were maintained in groups of 2 mice per cage. After observation of behavioural and physiological effects characteristic of isolation stress in the test mice, all isolated and control mice were mated after a 6½ month experimental, isolation period. No differences were observed in fertility and fecundity of the two groups of mothers. Analyses of developmental growth rates of the litters of the isolated versus control mothers showed significantly lower body weights in the test offspring at 3 and 4 weeks of age. The body weights of the female offspring remained significantly lower from the 4th to 11th weeks. The effects on the body weights of the male offspring declined and were no longer statistically significant at the 5th to 11 weeks. Locomotor activity at 4½ and 8 weeks of age was markedly or significantly higher in the male and female mice from isolated mothers. Tail-blood samples taken prior to autopsy at 5 and 11 weeks of age revealed significant decreases in the total leukocyte and eosinophil counts of both sexes. At the two ages, the absolute and relative spleen and thymus weights of the male and female offspring were markedly and/or significantly lower than the values observed in counterpart young from control females. Significant decreases were also observed in the absolute gonadal organ weights of both sexes at 11 weeks of age. The various data indicated inhibited growth rates, heightened locomotor activity and evasiveness, as well as evidence of increased adrenocortical function in the offspring from test mothers. The gonadal weight decreases suggested retarded gonadal development. Further studies using split-litter techniques are required to differentiate the effects of prenatal endocrine imbalances versus postnatal maternal influence (i. e., nursing care) on the offspring.



1983 ◽  
Vol 3 (8) ◽  
pp. 1381-1388 ◽  
Author(s):  
L P Villarreal ◽  
R T White

A late region deletion mutant of simian virus 40 (dl5) was previously shown to be deficient in the transport of nuclear RNA. This is a splice junction deletion that has lost the 3' end of an RNA leader, an intervening sequence, and the 5' end of the splice acceptor site on the body of the mRNA. In this report, we analyzed the steady-state structure of the untransported nuclear RNA. The 5' ends of this RNA are heterogeneous but contain a prominent 5' end at the normal position (nucleotide 325) in addition to several other prominent 5' ends not seen in wild-type RNA. The 3' end of this RNA does not occur at the usual position (nucleotide 2674) of polyadenylation; instead, this RNA is non-polyadenylated, with the 3' end occurring either downstream or upstream of the normal position.



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